1.0 unit looks good so far, though it's hard to really tell because last night's skip would have depleted the depot.
Can you monitor tonight? Since you are fairly new to the FD dance, SLGS would give you three options:
Between 150 and 200 (8.3-11.1 mmol/L), you have three options: a.) give nothing; b.) give a token dose (10-25% of the usual dose); c.) feed as usual, test in a couple of hours, and make a decision based on that value.
If you delay, your shot time tomorrow would be that much later. Another option is to wait 1/2 hour without feeding, and see if he comes up a bit more to a number you feel comfortable shooting.